参数资料
型号: IDT82V3288
厂商: Integrated Device Technology, Inc.
英文描述: WAN PLL
中文描述: 广域网锁相环
文件页数: 24/170页
文件大小: 1053K
代理商: IDT82V3288
IDT82V3288
WAN PLL
Functional Description
24
June 22, 2006
3.5
INPUT CLOCK QUALITY MONITORING
The qualities of all the input clocks are always monitored in the fol-
lowing aspects:
LOS (loss of signal) (only for IN1 and IN2)
Activity
Frequency
LOS monitoring is only conducted on IN1 and IN2. Activity and fre-
quency monitoring are conducted on all the input clocks.
The qualified clocks are available for T0/T4 DPLL selection. The T0
and T4 selected input clocks have to be monitored further. Refer to
Chapter 3.7 Selected Input Clock Monitoring
for details.
3.5.1
LOS MONITORING
IN1 and IN2 support the AMI input signal. LOS monitoring is con-
ducted on IN1 and IN2. A LOS event occurs when the amplitude of the
input clock falls below +0.6 Vp-p for 1 ms; the LOS event is cleared
when the amplitude rises higher than +1 Vp-p.
LOS status is indicated by the AMI1_LOS
1
/ AMI2_LOS
1
bit. If the
AMI1_LOS
2
/ AMI2_LOS
2
bit is ‘1’, the occurrence of LOS will trigger
an interrupt.
The input clock in LOS status is disqualified for clock selection for T0/
T4 DPLL.
3.5.2
ACTIVITY MONITORING
Activity is monitored by using an internal leaky bucket accumulator,
as shown in
Figure 4
.
Each input clock is assigned an internal leaky bucket accumulator.
The input clock is monitored for each period of 128 ms and the internal
leaky bucket accumulator increases by 1 when an event is detected; it
decreases by 1 if no event is detected within the period set by the decay
rate. The event is that an input clock drifts outside (>) ±500 ppm with
respect to the master clock within a 128 ms period.
There are four configurations (0 - 3) for a leaky bucket accumulator.
The leaky bucket configuration for an input clock is selected by the cor-
responding BUCKET_SEL[1:0] bits. Each leaky bucket configuration
consists of four elements: upper threshold, lower threshold, bucket size
and decay rate.
The bucket size is the capability of the accumulator. If the number of
the accumulated events reach the bucket size, the accumulator will stop
increasing even if further events are detected. The upper threshold is a
point above which a no-activity alarm is raised. The lower threshold is a
point below which the no-activity alarm is cleared. The decay rate is a
certain period during which the accumulator decreases by 1 if no event
is detected.
The leaky bucket configuration is programmed by one of four groups
of register bits: the BUCKET_SIZE_n_DATA[7:0]
bits,
the
UPPER_
THRESHOLD_n_DATA[7:0]
bits,
DATA[7:0] bits and the DECAY_RATE_n_DATA[1:0] bits respectively; ‘n’
is 0 ~ 3.
the
LOWER_THRESHOLD_n_
The no-activity alarm status of the input clock is indicated by the
INn_NO_ACTIVITY_ALARM bit (14
n
1).
The input clock with a no-activity alarm is disqualified for clock selec-
tion for T0/T4 DPLL.
Figure 4. Input Clock Activity Monitoring
Input Clock
Leaky Bucket Accumulator
No-activity Alarm Indication
Decay
Rate
Bucket Size
Upper Threshold
Lower Threshold
0
clock signal with no event
clock signal with events
相关PDF资料
PDF描述
IDT82V3288BC WAN PLL
IDT82V3288BCG WAN PLL
IDT85304-01 LOW SKEW, 1-TO-5 DIFFERENTIAL-TO-3.3V LVPECL FANOUT BUFFER
IDT85304 LOW SKEW, 1-TO-5 DIFFERENTIAL-TO-3.3V LVPECL FANOUT BUFFER
IDT88P8344 SPI EXCHANGE 4 x SPI-3 TO SPI-4 Issue 1.0
相关代理商/技术参数
参数描述
IDT82V3288BC 制造商:IDT 制造商全称:Integrated Device Technology 功能描述:WAN PLL
IDT82V3288BCG 功能描述:IC PLL WAN 3E STRATUM 2 208CABGA RoHS:是 类别:集成电路 (IC) >> 时钟/计时 - 专用 系列:- 标准包装:1,500 系列:- 类型:时钟缓冲器/驱动器 PLL:是 主要目的:- 输入:- 输出:- 电路数:- 比率 - 输入:输出:- 差分 - 输入:输出:- 频率 - 最大:- 电源电压:3.3V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:28-SSOP(0.209",5.30mm 宽) 供应商设备封装:28-SSOP 包装:带卷 (TR) 其它名称:93786AFT
IDT82V3352 制造商:IDT 制造商全称:Integrated Device Technology 功能描述:SYNCHRONOUS ETHERNET WAN PLL
IDT82V3355 制造商:IDT 制造商全称:Integrated Device Technology 功能描述:SYNCHRONOUS ETHERNET WAN PLL
IDT82V3355DKG 功能描述:IC PLL WAN SYNC ETH 64-TQFP RoHS:是 类别:集成电路 (IC) >> 时钟/计时 - 专用 系列:- 标准包装:1,500 系列:- 类型:时钟缓冲器/驱动器 PLL:是 主要目的:- 输入:- 输出:- 电路数:- 比率 - 输入:输出:- 差分 - 输入:输出:- 频率 - 最大:- 电源电压:3.3V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:28-SSOP(0.209",5.30mm 宽) 供应商设备封装:28-SSOP 包装:带卷 (TR) 其它名称:93786AFT